Dust storms or outbreaks are typical features of desert areas and only rarely occur in the temperate regions of our planet.
With the lack of rain over the past few weeks, the low temperatures and the lack of crop protecting the top soils, but espcecially the strong winds, conditions are optimal for dust outbreaks to occur.
Below you can see the meteorological conditions this morning shortly before 8 o' clock when the photo was taken: strong winds (8 Bft., >17m/s) straight from the East, a typical winter synoptic situation. The threshold wind velocity for dust emission from soils is 10 m/s and if all other conditions (particularly: bare soils) are met as well, there is nothing to stop a dust event from happening!
In the case of large agricultural land areas, such as exist in northern Germany, these dust outbreaks can lead to serious problems; in April 2011 a huge traffic accident, involving more than 40 cars, was caused by a severe reduction in visibility thanks to a dust outbreak.